This page provides information on the Color to Bump Map.
||Material Editor window|| > Material/Map Browser > Maps > V-Ray > VRayColor2Bump
map – A slot to load the map that you want to convert to a bump map.
height – A multiplier for the height of the bump effect. This basically makes the map brighter or darker.
bump delta scale – Controls the softness/sharpness of the bump effect. Lower values generate sharper transitions in the bump effect while higher values generate a softer looking bump effect.